Gynecomastia

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

David Perlstein, MD, MBA, FAAP

Dr. Perlstein received his Medical Degree from the University of Cincinnati and then completed his internship and residency in pediatrics at The New York Hospital, Cornell medical Center in New York City. After serving an additional year as Chief Pediatric Resident, he worked as a private practitioner and then was appointed Director of Ambulatory Pediatrics at St. Barnabas Hospital in the Bronx.

What is gynecomastia?

Gynecomastia is enlargement of the gland tissue of the male breast. During infancy, puberty, and in middle-aged to older men, gynecomastia can be common. Gynecomastia must be distinguished from pseudogynecomastia or lipomastia, which refers to the presence of fat deposits in the breast area of obese men. True gynecomastia results from growth of the glandular, or breast tissue, which is present in very small amounts in men. Gynecomastia is the most common reason for medical evaluation of the male breast.

What causes gynecomastia?

Gynecomastia results from an imbalance in hormone levels in which levels of estrogen (female hormones) are increased relative to levels of androgens (male hormones). Gynecomastia that occurs in normally-growing infant and pubertal boys that resolves on its own with time is known as physiologic gynecomastia.

All individuals, whether male or female, possess both female hormones (estrogens) and male hormones (androgens). During puberty, levels of these hormones may fluctuate and rise at different levels, resulting in a temporary state in which estrogen concentration is relatively high. Studies regarding the prevalence of gynecomastia in normal adolescents have yielded widely varying results, with prevalence estimates as low as 4% and as high as 69% of adolescent boys. These differences probably result from variations in what is perceived to be normal and the different ages of boys examined in the studies.

Gynecomastia caused by transient changes in hormone levels with growth usually disappears on its own within six months to two years. Occasionally, gynecomastia that develops in puberty persists beyond two years and is referred to as persistent pubertal gynecomastia.

Picture of male on the left with no gynecomastia and the male on the right with gynecomastia

A number of medical conditions may also result in gynecomastia:

Malnutrition and re-feeding (recovery from malnutrition) have both been shown to create a hormonal environment that may lead to gynecomastia. Similarly, cirrhosis of the liver alters normal hormone metabolism and may lead to gynecomastia.

Disorders of the male sex organs (testes) can result in decreased testosterone production and relatively high estrogen levels, leading to gynecomastia. These disorders may be genetic, such as Klinefelter's syndrome, or acquired due to trauma, infection, reduced blood flow, or aging. Testicular cancers may also secrete hormones that cause gynecomastia.

Other conditions that are associated with an altered hormonal environment in the body and may be associated with gynecomastia are chronic renal failure and hyperthyroidism. Rarely, cancers other than testicular tumors may produce hormones that can cause gynecomastia.

Gynecomastia can also be a side effect of a number of medications. Examples of drugs that can be associated with gynecomastia are listed below:

spironolactone (Aldactone), a diuretic that has anti-androgenic activity;

Enlarged Breast Tissue in Men

True gynecomastia is an enlargement of the male breast gland because of a hormonal imbalance, but the appearance of enlarged may breasts may be ascribed to pseudogynecomastia, a symptom of excess fat which deposits on the chest.